Saying yes or no puts Ironwolf in a hard position: it implies he might or might not have more information than he can say about the company, its efforts, its capabilities, and its status with NCSoft.
It's very much like the scene in The Godfather where Kay Adams tries to give Consigliere Tom Hagan a letter for the absent Michael Corleone. Hagan has to not take the letter--the bait, if you will--because the very act of taking that note from Kay would imply in a court of law that he knows the missing Michael's whereabouts, whether he truly knows or not.
In addition, the potential new team might even be comprised of current or former members from various companies--some out on the market already, some never with published experience. A safe wager, and likely a realistic one, is that the new team is a company without published experience as this company, even if its constituent members have experience working with many published games and titles. Thus, NCSoft has every right to ask what this company can do.
In addition to that, if we are dealing with an established company, NCSoft has just as much right to ask for a display of technical competence. Just because an established company could make, say, a great Bejeweled style game doesn't mean that it has the capability to oversee a great superhero MMO.
Therefore, with all the above put together, Ironwolf likely cannot and should not say anything that might even be taken as a hint toward yes or no. It would not only start rumor mills to churning and questions to asking, but it would also potentially endanger the status of the overall project. He took a big risk in saying one name that the company was not, earlier, and even that could have serious potential ramifications.
Granted, I can't speak for him, but this is what I firmly believe his position likely is, even without hearing from him personally. It's the safest way to go with the affair. It's not plausible deniability, but it is the next best thing: essentially, taking the Fifth.